Abstract: ARCO and Mother Nature Working in Harmony: Sheep Mountain CO₂ Reservoir

David J. Entzminger, Bill Gibbs, Larry Nugent, Stephen Rives

The Sheep Mountain CO₂ field is located in Huerfano County, Colorado, in the rugged terrain of the Sangre de Cristo Mountains. The field is operated by ARCO Oil and Gas Company who has carefully worked to minimize the impact to this scenic area. The rugged topography posed numerous operational challenges that included the drilling of multiple, 25 highly deviated wells from five drillsites. The use of five remote drillsites with their own gas treating and compression facilities created a more efficient gas gathering system in this rough terrain. The compressed gas is being fed to one trunk line that with the centralizing of facilities has greatly minimized the environmental disturbance.

ARCO produces from two distinct carbon dioxide gas bearing reservoirs; the upper horizon is the Cretaceous age, Dakota Formation and the lower horizon is the Jurassic age, Entrada Formation. The field was discovered in 1971 with the drilling of the Brooks Exploration No. 1 Garcia. It wasn't until 1983 that the field was put into production. The field will produce over one TCFG and id producing at a rate of 250 Mmcfgpd.

ARCO and the BLM have worked together to show that is possible to develop our natural resources with minimal disturbance to this beautiful area. A scenic overlook was built and dedicated in Fall 1993 which highlights the ARCO's commitment to the environment and petroleum industry.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994